ICD-10-CM 2027
ICD-10 code for ischemia
From the official ICD-10-CM alphabetic index entry “Ischemia, ischemic”. Page updated September 29, 2026.
About coding ischemia
The ICD-10-CM code for ischemia is I99.8 (Other disorder of circulatory system). The official index lists 46 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on I99.8.
Within I99, choose I99.8 (Other disorder of circulatory system) only when documentation doesn't support a more specific option: unspecified disorder of circulatory system (I99.9).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 302 (Atherosclerosis with MCC, relative weight 1.1984) and DRG 303 (Atherosclerosis without MCC, relative weight 0.6612), in MDC 05 (Diseases and Disorders of the Circulatory System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
More specific ischemia codes (official index)
- brain
- bowel (transient)
- acute K55.059 — Acute (reversible) ischemia of intestine, part and extent unspecified
- chronic K55.1 — Chronic vascular disorders of intestine
- due to mesenteric artery insufficiency K55.1 — Chronic vascular disorders of intestine
- cardiac (see Disease, heart, ischemic)
- cardiomyopathy I25.5 — Ischemic cardiomyopathy
- cerebral (chronic) (generalized) I67.82 — Cerebral ischemia
- arteriosclerotic I67.2 — Cerebral atherosclerosis
- intermittent G45.9 — Transient cerebral ischemic attack, unspecified
- newborn P91.0 — Neonatal cerebral ischemia
- recurrent focal G45.8 — Other transient cerebral ischemic attacks and related syndromes
- transient G45.9 — Transient cerebral ischemic attack, unspecified
- colon chronic (due to mesenteric artery insufficiency) K55.1 — Chronic vascular disorders of intestine
- coronary
- demand (coronary) I24.89 — Other forms of acute ischemic heart disease
- with myocardial infarction I21.A1 — Myocardial infarction type 2
- resulting in myocardial infarction I21.A1 — Myocardial infarction type 2
- heart (chronic or with a stated duration of over 4 weeks) I25.9 — Chronic ischemic heart disease, unspecified
- acute or with a stated duration of 4 weeks or less I24.9 — Acute ischemic heart disease, unspecified
- subacute I24.9 — Acute ischemic heart disease, unspecified
- infarction, muscle
- intestine (large) (small) (transient) K55.9 — Vascular disorder of intestine, unspecified
- acute K55.059 — Acute (reversible) ischemia of intestine, part and extent unspecified
- diffuse K55.052 — Diffuse acute (reversible) ischemia of intestine, part unspecified
- focal K55.051 — Focal (segmental) acute (reversible) ischemia of intestine, part unspecified
- large K55.039 — Acute (reversible) ischemia of large intestine, extent unspecified
- diffuse K55.032 — Diffuse acute (reversible) ischemia of large intestine
- focal K55.031 — Focal (segmental) acute (reversible) ischemia of large intestine
- small K55.019 — Acute (reversible) ischemia of small intestine, extent unspecified
- diffuse K55.012 — Diffuse acute (reversible) ischemia of small intestine
- focal K55.011 — Focal (segmental) acute (reversible) ischemia of small intestine
- chronic K55.1 — Chronic vascular disorders of intestine
- due to mesenteric artery insufficiency K55.1 — Chronic vascular disorders of intestine
- kidney N28.0 — Ischemia and infarction of kidney
- limb, critical
- limb-threatening, chronic
- mesenteric, acute K55.059 — Acute (reversible) ischemia of intestine, part and extent unspecified
- muscle, traumatic T79.6 — Traumatic ischemia of muscle
- myocardium, myocardial (chronic or with a stated duration of over 4 weeks) I25.9 — Chronic ischemic heart disease, unspecified
- acute, without myocardial infarction I51.3 — Intracardiac thrombosis, not elsewhere classified
- silent (asymptomatic) I25.6 — Silent myocardial ischemia
- transient of newborn P29.4 — Transient myocardial ischemia in newborn
- nipple, intraoperative and postprocedural N99.860 — Intraoperative and postprocedural nipple ischemia
- renal N28.0 — Ischemia and infarction of kidney
- retina, retinal
- small bowel
- acute K55.019 — Acute (reversible) ischemia of small intestine, extent unspecified
- diffuse K55.012 — Diffuse acute (reversible) ischemia of small intestine
- focal K55.011 — Focal (segmental) acute (reversible) ischemia of small intestine
- chronic K55.1 — Chronic vascular disorders of intestine
- due to mesenteric artery insufficiency K55.1 — Chronic vascular disorders of intestine
- spinal cord G95.11 — Acute infarction of spinal cord (embolic) (nonembolic)
- subendocardial
- supply (coronary) I25.9 — Chronic ischemic heart disease, unspecified
- due to vasospasm I20.1 — Angina pectoris with documented spasm
Common questions about ischemia ICD-10 codes
What is the ICD-10 code for ischemia?
- I99.8 — Other disorder of circulatory system. More specific codes apply when the documentation supports them: K55.059, K55.1, K55.1, I25.5 and others below.
What is the ICD-10 code for cardiomyopathy ischemia?
- I25.5 — Ischemic cardiomyopathy.
What is the ICD-10 code for cerebral ischemia?
- I67.82 — Cerebral ischemia.
What is the ICD-10 code for colon chronic ischemia?
- K55.1 — Chronic vascular disorders of intestine.
What is the ICD-10 code for demand ischemia?
- I24.89 — Other forms of acute ischemic heart disease.
What is the ICD-10 code for heart ischemia?
- I25.9 — Chronic ischemic heart disease, unspecified.
What is the ICD-10 code for intestine ischemia?
- K55.9 — Vascular disorder of intestine, unspecified.
Is I99.8 billable?
- Yes. I99.8 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can I99.8 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict I99.8 as a principal diagnosis.
Is I99.8 a CC or MCC?
- No. I99.8 is neither a CC nor an MCC under MS-DRG v44.0.